*,body,div,ul{
     margin: 0;  padding: 0;
 }
body{
    background: url("../img/index_bg.jpg") ;
    background-size:cover;
    background-attachment: scroll;
    position: relative;
}
.head{
    text-align: center;
}
.head img {
    width: 1000px;
}
.mid {
    display: block;
    background-color: #ffffff;
    width: 940px;
    margin-left: 189px;
    margin-top: -4px;
    height: 100%;
}
.demo_line_01{
    position: relative;
    height:1px;
    width:920px;
    background:#D8D8D8;
    margin-left: 10px;
    top: 10px;
}
.demo_line_02{
    position: relative;
    height:3px;
    width:200px;
    background:#3300FF;
    margin-left: 10px;
    top: 8px;
}
.wel b {
    color: #3300FF;
    font-size: larger;
    padding: 10px;
}
.wel u {
    color: #3300FF;
}
.wel{
    display: block;
    margin-left: 10px;
}
.wel_1{
    position: relative;
    display: block;
    top: 18px;
}
.demo_line_03{
    position: relative;
    height:1px;
    width:800px;
    background:#D8D8D8;
    margin-left: 100px;
    top: 10px;
}
.tab1{
    margin-top: 30px;
    text-align:center;
}
table, tr，td
{
    margin: 0 auto;
    /*border-left:1px solid #D8D8D8;*/
    border-left:solid 0px red;
}
table
{

    background-color: #E8E8E8;
}
.tab2{
    margin-top: 30px;
    margin-bottom: 30px;
    text-align:center
}